Percussive tool



Patented Oct. 15, 1929 truste UNITEDSTATES PATENT OFFICE WILLIAM R. WILLIAMS, OF KENT, OHIO, ASSIGNGR TO TI-IE DAVEY TREE EXPERT OO., OF KENT, OHIO, A CORPORATION OF OHIO PERCUSSIVE TOOL Application led March 22, 1927.

My said invention relates to a percussive tool having a holder or chuck for a tool e. ot the reciprocatory pneumatic type in which the tool is not operated until it has been placed against the work and i'orced back against a rapidly vibrating plunger'. In tree surgery, to which my device is peculiarly adapted, it is often necessary to work with the tool pointing upward andm in such cases the tool, here shown as a chisel, will tall back repeatedly on the vibrating plunger and be thrown up against the shoulder limiting its outward movement, with the result that the said shoulder and the coacting shoulder of the tool will be injured by the unnecessary hammering. It is an object ot my invention to avoid this hammering action. lVhether the tool points upward or horizontally it is fre quently driven with great :torce out of the chuck it it happens to be turned into releasing position and so may do serious damage, which is avoided according to my invention by the use ot an improved retainer.

Another object of my invention is to pro vide a quickly detachable connection for the tool.

Referring to the drawings, which are made a part ot this application and in which similar reference characters denote similar parts: y

Fig. l is an elevation of the forward end ot a pneumatic hammer' chuck and a tool operated thereby, with certain parts broken away,

Fig. 2, a. fragmentary vertical section of the device in working position,

Fig. 3, an elevation of a chuck casing o1 sleeve,

Fig. 4, an end view oi: the saine,

Fig. 5, an end view of the chuck housing and plunger with the tool and associated parts omitted,

F 6, a detail of a key ring,

Fig. 7, a section on line 7--7 of Fig. 2,

Fig. 8, a detail of a locating ring,

Fig. 9, a side view of the same,

Fig. l0, a detail of a locking ring,

Fig. 1l, a side view of the same,

gig. 12, a section oi' the tool on line 1,2-12, an

-20 and serves as a guard to prevent Serial No. 177,290.

Fig. 13, a section of the tool shank on line 12;-13

In the drawings, reference character 2O indicates the reduced end of the housing a suitable tool holder containing a vibratory percussion member 19 tor actuating the tool 2l by blows ot the percussion member, which is mounted for longitudinal movement in the housing 22.

A knurled tool retainer 28 encloses the end injury to the operators hands or clothing by the moving parts inside said retainer. At its forward end the retainer has an opening 2a corresponding in shape to a collar 25 on the tool(Fig. 7), and at opposite sides or the opening there are two shoulders 26 (Fig. Li) on which the enlarged parts of the collar 25 may rest, The housing has a nonecircular rccess at 27 (Fig. 5) providing a seat for the correspondingly-shaped shank 27 of the tool.

Near the opposite end ol the retainer there is a shoulder on which rests a locating ring 28 provided with two pins 2f), said ring' bearing at its rear side against a shoulder on the housing 22. The pins 29 extend into apertures 30 in a locking ring 8l (Fig. l0) and the retainer 23 has shallow recesses cooperating with apertures 30 to receive the pins and so provide for relative positioning oiE the retainer and the ring 3l. Screws 32 pass through holes 33 in the retainer and engage threaded apertures Sli in the locking ring to fix said parts together.

A spring 35 surrounds the housing 20, said spring bearing at one end against locking ring 31 and at the other against akey ring 3G (Fig. 6) having an elongated central opening at 37 andrecesses at 38. The central opening corresponds to the approximately oblong shapeof the lower end 89 ot the housing (Fig. 5) and the recesses 38 correspond to the ears t0 whereby the ring may belslipped over the end ot the housing, given quarter turn, and permitted to seat itseli' with the ears in recesses 38 whereby it is locked against ro` tation about the housing.

The device `is assei'nbled by positioning the locating ring 28 as in Fig. 2, then the loci-ri ing ring 3l and the spring 35, then the key Y ring 36 ispositioned in the manner above deother ringsin place.

scribed, sothat it holds the spring and the Then the retainer 23 may be slipped on, lit being guided to place by pins 29 and secured by screws 32. The retainer is now given aquarterV turn by hand to bring the opening 24 in to position to allow the shank 27 to enter its seat, after whiehthe retainer is turned back a quarter turn Vto secure the tool in place.

It Will lbe seen that the tool can be very quickly released and replaced by the means described and that the friction between the housing' and the locating ring due to the spring will preventaecidental rotation of the retainer. In addition to this the spring 35 serves to cushion the movement of the retainer under the impact of its impelling means andso prevent injury to the collar 25 and the ears 26, while also holding the tool against rotation relatively to the housing.

'It will be obvious to those skilled in the art that my Vconstruction Vas disclosed may be varied in many Ways Without departing from the spiritof the inventionand therefore I do not limit Ymyself to the specific form of the invention shown in the Vdrawings and described in the specification, but only as indicatedin the appended claims.

YHaving thus fully described my said invention, what I claim as new and desire to secure by Letters Patent is:

1. The combination With a housing having` a bore, an impelling member in the bore, a tool having a non-cireular shank fitting in a correspondingly shaped part of t-he bore, a ytool retainer about the outer end of the hous-k ing, and a spring inside the retainer for forcing the retainer toward the inner end of the housing, of interengaging means on the retainer and tool adapted to release the tool on rotation of the retainer aboutthe housing, and means for frietionally resisting rotation of the housing comprising oppositely facing shoulders on the housing and the retainer,'a locating ring fitting between said shoulders, and means on the housing and the retainer for holding the spring under compression, substantially as set forth.

2. Thejcombination-with Ya housing h aving a bore, an impelling member in the bore, a-v tool Vhavinga non-circular shankfitting in a correspondingly shaped part of the bore, atool retainer about the outer end of the housing, and aspring inside the retainer for forcing the retainer toward the inner Vend of the housing, of intereng'aging means on the retainer and tool adapted to release the tool on rotation of the retainer aboutthe housing, and lmeans for frictionallyv resistf ing rotation ofthe lretainer comprising oppositely facing shoulders von therhousing and the retainer, a locating ring fitting between said shoulders, means on the housing for supporting the outer end of the spring, and

a locking ring fixed to the interior of the retainer in position to compress said spring said locking ring having its upper face on a level with the shoulder on the retainer, whereby said locating ring supports the locking ring against shocks tending to separate it from the retainer and said locating ring also acts as a brake against circumferential movement of the retainer.

3. The combination with a housing having a bore, an impelling member in the bore, a tool having a non-circular shank fitting in a correspondingly shaped part of the bore, a tool retainer about the outer end of the housing, and a spring inside the retainer for forcing the retainer toward the inner end of the housing, of interengaging means on the retainer and tool adapted to release the tool on rotation of the retainer about the housi ing, and means for frictionally resistiim rotation of the retainer comprising oppositely facing shoulders on the housing and the retainer, a locating ring fitting in the retainer with its inner face in the same plane as that of t-he shoulder in the retainer, said lock` ing ring holding the spring under compression, screws passing through the retainer into the locking ring, and pins on the loeating ring entering mating recesses in the locking ring and the retainer to insure registration of the screw holes in said parts, substantially as set forth.

4. The combination with a housing having a bore, an impelling member in the bore, a tool having a non-circular shank fitting in a correspondingly shaped part of the bore, a tool retainer about the outer end of thc housing, and a spring inside the retainer for forcing the retainer toward the inner end of the housing, of interengaging means on the retainer and tool adapted to release the tool on rotation of the retainer about the housing, means for frictionally resisting rotation of the retainer comprising a shoulder on the housing, and means carried by the retainer including a face normally held in engagement with said shoulder by said spring, substantially as set forth.

In testimonyv whereof I aiix my signature.

WILLIAM R. WILLIAMS. 

